Comment on the dramatic techniques of Alan Bennett in A Cream Cracker Under the Settee Essay Example

Comment on the dramatic techniques of Alan Bennett in A Cream Cracker Under the Settee Essay A Cream Cracker Under the Settee is a monologue, which is a play with a single character. The character is Doris, a seventy five year old widow, who lives on her own. She has home help that visits once a week. In this monologue form, information is gradually revealed by the one character Doris. We find out shes had an unhappy life; eventually we find out why. Doris looks back nostalgically on her childhood and early marriage, the times in her life when she was truly happy. Something changed her life. At first the reader is unaware and even misled by Bennett. Doris describes Wilfred as dad, and thus he misleads the viewer into thinking there was a baby. We later find there was a baby, but it was a stillbirth. Doris didnt like the midwifes attitude when she wrapped the baby in newspaper then put it in a shoebox. Doris felt she was treating it like dirt. She says, He wasnt dirty, little thing. This could have been the start of Doriss hygiene obsession. Also, Wilfred did not help her much. Her husband wanted to get a dog instead. Her marriage wasnt great, Wilfred was a dreamer and frustrated Doris. We will write a custom essay sample on Comment on the dramatic techniques of Alan Bennett in A Cream Cracker Under the Settee specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Comment on the dramatic techniques of Alan Bennett in A Cream Cracker Under the Settee specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Comment on the dramatic techniques of Alan Bennett in A Cream Cracker Under the Settee specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Wilfred started little projects like an allotment, but never did anything with them, and then he moved onto something else. Doris still misses him though. We know this because she talks to the wedding photo, which also shows she is lonely. We know Doris has had an unhappy past: she is also having an unhappy present. There is an immediate problem. Doris has been dusting and had an accident, she hurt her leg and its getting worse. Part of Doriss unhappiness is her loneliness, she has no family and no friends: we were always on our own. Me and Wilfred. We werent gregarious. This is exacerbated because Doris hasnt moved with the times; she doesnt like change and new social patterns. Doriss main cause of unhappiness is her home-helper Zulema. She patronises Doris and keeps threatening her with Stafford House. Doris feels she is a prisoner, referring to the Zulema regime. All the information I have considered is gradually revealed to the audience using a number of dramatic techniques. Doris uses non-standard English, like thems her leaves. She also has a local dialect and uses words like squatting instead of placing. This establishes her character: she is probably working class but when she uses words like surreptitious and gregarious Bennett suggests she is quite clever. Bennett emphasises things about Doris by using recurrent themes. Doris has a hygiene obsession. She talks about cleanliness a lot and is prejudiced against people in Stafford House because she thinks they are unclean. She talks about her husband Wilfred frequently and speaks to the photo of him. Another technique Bennett uses is reported speech: this brings in other characters so the monologue is more interesting. An example of this is Zulema we form our impression of the character from what Doris tells us she says: youre on trial here. Sometimes Doris has an imagined conversation where she plans what shell say to Zulema: dont Stafford House me. Doris does this because she would like to say it, but really she wouldnt dare. Bennett also uses direct address where she speaks to the audience. She says, Would you credit it? This is to get more involvement from the viewers. A cream cracker under the settee was written for television, so it uses a number of dramatic techniques to do with performance. These include, set, costume, lighting and music. The set gives the audience important information at the start of the monologue about the character and the plot. The set is old fashioned. The carpet is brown and beige and patterned, the room is dull with few ornaments, and this could mean she is poor. Right away you can tell something has happened: there is a buffet on its side and a cracked photo on the hearth, and Doris has a duster in her hand. The costume used is old fashioned which reflects Doris. She has a blue floral frock which she says shes had for years. She wears a pink knitted cardigan, horned rimmed glasses and tights. All these are very practical clothes. Another technique used in the performance is the lighting. In the morning Doris is sitting in front of the window and she is backlit. When she is against the sideboard she is away from the window so it is less bright. Doris later moves to the door where it is darker still. In the evening she is sat by the sofa and the room is orange due to the streetlights. There are two dramatic functions of the lighting. One of them is to indicate the passage of time. Doris does not tell the viewer what time it is. The second is as a metaphor: the last stage direction is light fades, and this could indicate Doriss death. The last two dramatic techniques of the performance are the use of music and the camera. At the start the music sounds sad and lonely this sets the mood straight away as it is depressing. The instruments are piano and brass, solo instruments that are alone, like Doris. There is a single camera which is linked to the music, zooming in to emphasise emotional moments. The camera does not move around Doris so any movement is effective.

Gadget Toy Companys Network

Gadget Toy Companys Network Drawing Network Gadget Toy Company’s NetworkAdvertising We will write a custom essay sample on Gadget Toy Company’s Network specifically for you for only $16.05 $11/page Learn More Purpose of Critical Path A critical path helps the management to identify the most crucial activity in every project. A critical path is the longest time that a project can take to be completed. At the same time, it is the shortest time that a project can take because it has no float time. Identification of the critical path helps the management in allocating resources and directing the activities in order to accomplish the project within the stipulated time schedule (Webb, 2002). The critical path shows activities whose duration can be reduced to reduce the overall production duration. Otherwise, reducing activities, which do not form part of the critical path, increases cost without reducing the overall project duration. The critical path outlines the most impor tant sets of activities which when implemented the project goals will be realized (Webb, 2002).Advertising Looking for essay on business economics? Let's see if we can help you! Get your first paper with 15% OFF Learn More Tracking the project using the Critical path Critical path analysis allows management to monitor the development of the project while tracing its achievement (Webb, 2002). Through the critical path, the management can tell whether they will be able to meet their targeted goals or not. Any deviation arising are easily detected and remedial action are employed promptly to address any shortcomings. Moreover, the critical path helps the management to identify activities, which can be delayed in order to allocate limited resources to other activities without affecting the project duration. On the same note, the critical path helps the management make good judgments pertaining future changes in costs and other eventualities. To hasten project an alysis, Critical path is used to develop Gantt Charts, which illustrates the sequence in which activities are implemented (Webb, 2002). Gantt charts also shows which activities should be completed first before initiating others, without the critical path the management may find it difficult to understand which activities to implement first. Ways Preventing Project delays To keep the project on track the management may decide to switch some resource from an activity with float time to a critical activity. This process helps to ensure that all the critical activities are ran smoothly while delaying other activities, which are not critical (Webb, 2002). Delaying such projects does not affect the overall project duration. From the network drawn above, the management of Gadget Company may opt to delay activity D (Deliver material) to allocate more time for installing tools (activity E). Secondly, the management may opt to hire additional labor, or provide for overtime (work on weekends) in order to reinstate the project back on track. However such as measure means requires additional allocation of money to hire more labor. The other way that a project can be kept on track is by working at night so as to make up for the lost time. The other alternative would involve increasing supply so as to hasten the rate project completion time. However, any decision to increase labor and supply means incurring extra cost, which may not be readily available.Advertising We will write a custom essay sample on Gadget Toy Company’s Network specifically for you for only $16.05 $11/page Learn More Finally, Gadget Toy may opt to crash one of the critical activities to reduce the operation time. Crashing an activity involves reducing the duration taken by an activity at a higher cost. Crashing cost depends on the time reduced on top of the original cost budgeted for that activity. Ways of linking interrelated projects There are several ways of linking mu ltiple projects with interdependencies using the critical path method namely: Performance Evaluation and Review Technique (PERT), Earned Value Management (EVM) Graphical Evaluation and Review Technique (GERT) Program Evaluation and Review technique According to Webb (2002) PERT forms the foundation of planning and forecasting thereby enabling the management to prepare in advance. Apart from this, PERT provide management with ample time when it comes to decisions making especially in interrelated projects and portfolio projects. This management tool not only helps in effective utilization of resources of resource but it also ensures that all projects are completed within the stipulated time. This is made possible by visibility provided by the project as single process is used for various projects. Finally, PERT is a reliable tool for handling uncertainties because all projects are laid in a horizontal manner that makes it easier for management to detect any delay or slack. Earned V alue Management (EVM) EVM is another popular method of linking project that is being used in the modern management practices. It involves analyzing various projects, portfolios and businesses, it provide management with information tools to handle several projects at ago. In addition, EVM provides insight for future changes in project implementation. In order for management to adequately prepare for the impending uncertainties, EVM provides room for prioritizing some projects while delaying others in order to facility a mutual relationship between them. Graphical Evaluation and Review Technique (GERT) GERT operates in a similar way as the Pert but have some differences because it allow looping, project branching and multiple projects handling. GERT is an improvement on PERT because it elaborates the status of a project whether it is successful or not. Incase a project branch fails to deliver the expected results the management switches attention to other branch.Advertising Looking for essay on business economics? Let's see if we can help you! Get your first paper with 15% OFF Learn More Benefits of Linking Projects Linking project has become a popular method of handling various projects that are interrelated, through linking such project the management derives many benefits. Firstly, the management improves planning as linkages facilitate projecting the future trends of the projects in terms of time and money requirement. With such a foresight the management plans in advance on how to overcome such challenges by delaying some projects or by increasing labor to meet the stipulated deadline. Pennypacker and Dye (1999) asserts that connecting several interrelated projects provides room for identifying repetitive activities. This helps in streamlining operation since the criteria for handling this project remains similar from one set of activities to the other. Repeated action promotes managers dexterity and confidence in handling similar projects in future thereby improving their efficiency. Integrating projects helps the managers to reschedule activities to display p roject interdependencies and how such relationships stretch the available resources. However, with this challenge in the mind the manager ensures proper prioritization of activities for efficiency utilization of limited resources. With the modern state-of-the- art, linking projects has also provided room for development of software to handles multi-projects in one go. Such development has acted to the best interest of managers whose role has been reduced to monitoring the progress and checking for compliance with the set time limits. Additionally, the management has the challenge of dealing with conflicts between projects and ensuring optimal allocation of resource between such projects. Moreover, the managers have the obligation of allocating resources according to the priorities set for the conflicting projects. Nevertheless, setting priority for activities forming part of the critical path has proved to be cumbersome and as a result, the management should always remain vigilant a t such critical moments (Pennypacker and Dye, 1999). Reference List Pennypacker, S.J. Dye, D. L. (1999). Project Portfolio Management, Selecting and Prioritizing Projects for Competitive Advantage. West Chester: Centre for Business Practices. Webb, A. (2002). Project Management for Successful Product Innovation. Hampshire: Gower Publisher

Does Zero Tolerance Policing 'work' Essay Example | Topics and Well Written Essays - 3750 words

Does Zero Tolerance Policing 'work' - Essay Example The administrators objected to having to enforce the principle of zero tolerance on the grounds that they would have to go in with a police escort, even on the basis of a sliver of a rumour about a picture you don't like. Defenders of the policy reply that it indicates a greater willingness to take such complaints seriously. This type of policy of reversing the burden of proof is a species of argumentum ad ignorantiam of the following form: if you can't prove that you are not guilty, then it is presumed that you are guilty. Normally, the burden is on the accuser to provide evidence or corroboration of the charge. Admittedly, where an event took place privately between two people, with no physical evidence of harm, it is generally hard to prove such objective corroboration. The solution advocated by the zero tolerance principle is to shift the burden of disproof of the charge onto the side of the accused party. If he can't furnish such evidence, the conclusion we should draw by the ad ignorantiam argument is that he is guilty. Is this a reasonable or fallacious use of the argument from ignorance This is a hotly disputed question at the moment. Defenders of zero tolerance argue that the application of the argument from ignorance, as a reasonable argument in this instance, is justified by argument from consequences: namely, those women are at present suffering from abuse to such a degree that anyone who opposes zero tolerance is causing the deaths of women. Opponents of the principle also base their opposition on the argument from consequences. They argue that the policy of zero tolerance is producing many innocent victims of false charges of abuse, and having a disastrous effect on families. Opponents of the policy also argue that the advocates of zero tolerance are focusing only on the consequences as they affect one group, and ignoring the impact on anyone who is not a member of this group. They see this as a form of self-interested bargaining or advocacy dialogue taking the place of a more rational and objective type of deliberation or critical discussion that takes all points of view into account. At any rate, on this controversial issue, the central question directly relates to the argumentum ad ignorantiam as a type of argument. Is it reasonable or fallacious in this case And what are the grounds for justifying one opinion or the other Significantly, zero tolerance policing, with its more assertive and control oriented message, seems to have struck a chord in recent years. An increasing number of public-initiated police contacts are crime-related, especially in inner-city areas and in a time of stretched resources many have argued that police duties should be more closely restricted to crime-work. This was the dominant message behind the setting up inquiry into core policing tasks, which, despite denials, was envisaged as clearing the way towards the privatization of alleged 'peripheral' police-work. While the conclusions of the

Productive and Counterproductive Behaviors Paper Essay

Productive and Counterproductive Behaviors Paper - Essay Example For example, an employ who is ready to work overtime for the completion of certain project will definitely improve the productivity of the organization. On the other hand the one who never finishes his work in time will always be a burden to the organization. Even a single employ can sometimes spoil the entire production activity of a manufacturing unit. Absenteeism, accidents, deviant behaviors, and turnover are some of the counterproductive behaviors. (Salgado) Unnecessary and uninformed absenteeism can create problems to the overall activities of an organization since the manager needs to find substitutes only at the last moments and may be forced to postpone certain activities which will reduce the productivity of the organization. Deviant behaviors such as breaking company rules and norms, turnover behavior such as slow adaptation to labor scheduling to cover lost productivity etc can affect the organization drastically. Making helpful comments during discussion, making notes (or other writing) to organize efforts, exhibits aggressive attention to detail, exhibits constant and effective creative thinking, exhibits leadership, skillful time management, punctual (starts work on time) works to end of time; doesnt knock off early doesnt wander or distract during work time etc are productive behaviors. (Productive Behaviors) An executive who is working in Production Planning Control (PPC) department of an organization is responsible for planning the entire production activities of a shift based on the inventory he has taken. If he fails to record the correct inventory his planning will go wrong and hence the entire production activities will be disturbed due to poor planning and the organization’s productivity in that shift will be reduced considerably. On the other hand another planning executive who is able to

The Causes of Occupational Stress and Its Effects on Overall Dissertation

The Causes of Occupational Stress and Its Effects on Overall Performance within Oil and Gas Industry - Dissertation Example Stress can be described as a reaction or feeling that an individual experiences. The examples of workplace stressor include being overworked and time pressures. It is a condition or difficult situation that disturb or is expected to upset the normal physiological functioning of an individual. It is the response of a body which is harmful in nature that tends to disturb its physiological equilibrium (Cooper & Et. Al., 2010). Response Based Stress Response based stress is the form of strain, pressure and tension. The approach of response based stress is to understand stress which appears to describe an intangible happening hence it can be analysed as outcome. In research terms, it can be explained as dependant variable, where the major hypothetical field is the sign of stress (Cooper & Et. Al., 2010). . Occupational Stress There is a negative upsetting experience within an individual in a workplace which is complex as well as dynamic process and directly or indirectly affects the physiological factors of individuals such as gastrointestinal disorders, mental trauma, musculoskeletal pain and cardiovascular diseases. It is risky to work in a stressful environment as it may be physically harmful which is called as symptom for psychological distress (Clarke & Cooper, 2004). According to National Institute of Occupational Safety and Health, the number of cumulative trauma of the US employees has increased and there were large number of personal injuries in the United Kingdom. The cumulative trauma mentally affects a person due to continuous exposure to occupational stress (Clarke & Cooper, 2004). A various number of studies in the earlier days have shown that occupational stress has been considered as the prime risky aspect for mental illness among the workers in an occupation. It has been analysed by Stansfeld and Candy that combining high demands with low decision latitude along with high efforts with low rewards were eventually a factor which causes mental disorders (Stansfeld & Candy, 2006). Causes The cause of stress depends upon structure of the workplace and type of job that an individual does in an organisation. The stress is caused due to following reasons: Demand: The demand factor is the main cause for stress; it depends upon workload of an in dividual. The work can expose an individual to different physical risks such as fire, noise, chemicals and others. Control: An individual gets involved in making decision and influences others in a workplace. Relationship: The bad relationship with team members,

Radial Ball Bearing Material

Radial Ball Bearing Material You are tasked with selecting a material that is suitable for the balls in a radial ball bearing such as the one shown in Fig. 1. Radial ball bearings although intended primarily for radial loads, will also carry a certain amount of thrust.    Ball Figure 1 Ball bearing The following details are known in relation to radial ball bearing design: Youngs modulus should have a minimum of 200 GPa. The compressive strength should have a value à ¯Ã¢â‚¬Å¡Ã‚ ³ 300 MPa. The balls must not fail under load. It can be assumed that the contact stress can be modelled for a sphere on a flat (see Fig. 1). An assumption should be made that the material for the ball and the raceway are the same and therefore they have the same moduli and Poissons ratio has a value of 1/3. The balls should be light. Material selection process. This refers to selecting a material that meets all the constraints and objective below. Design requirements: Table 1 Table of design requirements Function   Suitable for balls in a radial ball bearing Constraints Youngs modulus must be greater than 200 Gpa. Compressive strength should not have a value of less than 300Mpa. (Assumption)Moduli and Poissons ratio being the same (ratio of ). Objectives The balls must not fail under load, contact should be modelled for a sphere on a flat. The balls should be light. Free variables Cross sectional area Material choice Mass of ball Below is a figure of all materials with a mechanical property (Youngs modulus greater than 200Gpa and Compressive strength greater than 300Mps) against density: Seen below is a table of the materials and their corresponding Youngs modulus. Table 2 Table of materials Name Youngs modulus (GPa) Tungsten carbides 625 700 Boron carbide 440 472 Silicon carbide 400 460 Alumina 343 390 Tungsten alloys 310 380 Aluminium nitride 302 348 Silicon nitride 290 318 Zirconia 200 250 Nickel-based super alloys 150 245 Nickel-chromium alloys 200 220 Nickel 190 220 Low alloy steel 205 217 Medium carbon steel 200 216 Low carbon steel 200 215 High carbon steel 200 215 Stainless steel 210 Although seen above, 16 values have passed the requirements so far, further analysis will be conducted, and this can be seen below; The below table illustrates the materials that meet the design requirements, the table is ranked based on Youngs modulus, from highest modulus to lowest. The Compressive strength of the material must also be considered, a minimum compressive strength of 300MPa must apply. The table below illustrates each materials Youngs modulus and corresponding compressive strength. Table 3 Materials with Youngs modulus and compressive strengths that meet design requirements (density also noted) Name Youngs modulus (GPa) Compressive strength (MPa) Tungsten carbides 625 700 3.35e3 6.83e3 Boron carbide 440 472 2.58e3 5.69e3 Silicon carbide 400 460 690 5.5e3 Alumina 343 390 690 5.5e3 Tungsten alloys 310 380 555 800 Aluminium nitride 302 348 1.97e3 2.5e3 Silicon nitride 290 318 524 5.5e3 Zirconia 200 250 3.6e3 5.2e3 Nickel-based super alloys 150 245 300 1.9e3 Nickel-chromium alloys 200 220 365 460 Nickel 190 220 70 1e3 Low alloy steel 205 217 400 1.5e3 Medium carbon steel 200 216 305 1.76e3 Low carbon steel 200 215 250 395 High carbon steel 200 215 335 1.16e3 Stainless steel 189 210 170 1e3 Below is a bubble chart of Youngs modulus versus compressive strength: Figure 2 Bubble chart of Youngs modulus of Compressive strength The above figure is on a logarithmic scale. Only materials that have passed the requirements were plotted. When surfaces are placed in contact they touch at one or a few discrete points. If the surfaces are loaded, the contacts flatten elastically and the contact areas grow until failure of some sort occurs. (Duffy, 2010) Compressive stress causes this. As the requirements state; should be modelled as a sphere on a flat, this allows the student to use following formulae (contact stresses); Figure 3 Sphere on a flat (Duffy, 2010) (Yield Stress)   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The following is subbed in to produce the below: x x x x = = The mass of the sphere must be derived, this is done below; Where is density and is volume Volume of a sphere is denoted as: m= The student knows the objective is to minimise the mass of the ball, the derivation above is done on that basis and results in the equation being flipped above. From the material selection index above, the equation can be related in the logarithmic scale: = This results in: This now means the slope can be known to be = 0.222 The above value is known as an index line; Index lines can be used to compare the performance of different materials, and to find replacement materials. Materials that are on the line will all perform equally well in each design. Materials above the line have a higher performance index and will therefore perform better; those below the line have a lower index value. (Edupack, 2006) The below bubble chart illustrates the material selection process using the slope; Figure 4 Material selection with material index As seen from above, with a material index of 0.222 the following two materials passed (whole record is within the selection was used); Name Index slope =0.2222 Silicon nitride 6.55e101 Zirconia 1.66e100 As seen from above the materials are both ceramic. An additional chart plotting the materials costs can also be seen below; Figure 5 Price of selected material Figure 6 Price of selected material Pass only A table of the materials cost can also be seen below; Table 4 Table of costs Name Price(EUR/kg) Zirconia 17.1-24.7 Silicon nitride 32.3-49.4 (i) It has been identified that both Youngs modulus and compressive strength are important material properties when selectin ball bearings, below is a detailed summary of why each property is important; Youngs modulus refers to a materials elastic modulus. This determines the stiffness of a solid material. This is a proportional (constant) between stress as long as stress is less than the yield point. This results in a smaller strain with the same stress in a stiffer material. In relation to a ball bearing Youngs modulus of Silicon nitride is about 1.5 times that of steel, meaning a smaller contact surface is present when there is a high contact pressure. Hertz theory means the maximum load for combination steel- Silicon nitride reduced with 30%. In relation to the contact of the bearing we know it will be a sphere on a flat. The balls within a bearing are going to experience both an axial and radial force. If the force is too great for the material this may result in deformation (changing of shape). This affects the ball bearings ability to perform, this can be compared to as a wheel on a car, if it is flat may result in a pulling motion. If severe deformation occurred this may result in the bearing not allowing for rotation. This means that Youngs modulus is important when selecting materials for ball bearings. Youngs modulus mathematical representation; It is noted from CES EduPack that silicon nitride is used mostly for ball bearings the Youngs modulus is known to be; 290-318 GPa (Edupack, 2006) Compressive strength refers to a materials resistance to compressive stress. This is when a force is applied in an inwards direction in the material. It is opposite to tensile stress. As a ball bearing is going to have one point of contact, (below) compressive strength is an important element in choosing the material. This is due to the radial forces applied when the ball is in the raceway. Once again, if the radial force is greater than the materials compressive strength abilities this will result in deformation. This will affect the bearings performance. Compressive strength can be up to 10 times greater than tensile stress. Ceramic material has a good compressive strength due to crack propagation, since there are more internal cracks in ceramics (than most materials) if placed under tension cracks will propagate and produce failure where if it is placed under compression it works in the opposite manner. Compressive strength mathematical representation; It is noted from CES EduPack that silicon nitride is used mostly for ball bearings the compressive strength is known to be; 524-5.5e3 MPa   (Edupack, 2006) (ii) The other material properties of Silicon Nitride which lead to superior operating performance can be seen below; General properties Density3.1e3-3.4e3kg/m^3 Price*32.3-49.4EUR/kg Date first used1958 Mechanical properties Youngs modulus290-318GPa Shear modulus*100-128GPa Bulk modulus*210-232GPa Poissons ratio0.26-0.28 Yield strength (elastic limit)*600-720MPa Tensile strength600-720MPa Compressive strength524-5.5e3MPa Elongation0% strain Hardness Vickers1.4e3-1.6e3HV Fatigue strength at 10^7 cycles*300-500MPa Fracture toughness4-6. 7MPa.m^0.5 Mechanical loss coefficient (tan delta)*2e-5-5e-5 Thermal properties Melting point2.39e3-2.5e3 °C Maximum service temperature1e3-1.2e3 °C Minimum service temperature-272271 °C Thermal conductor or insulator?Good conductor Thermal conductivity22-30W/m. °C Specific heat capacity670-800J/kg. °C Thermal expansion coefficient3.2-3.6 µstrain/ °C Electrical properties Electrical conductor or insulator?Good insulator Electrical resistivity1e20-1e21 µohm.cm Dielectric constant (relative permittivity)7.9-8.1 Dissipation factor (dielectric loss tangent)*5e-4-7e-4 Dielectric strength (dielectric breakdown)*11-131000000 V/m Optical properties TransparencyTranslucent Refractive index1.95-2 Processability Moldability2-3 Weldability1-2 Eco properties Embodied energy, primary production116-128MJ/kg CO2 footprint, primary production4.63-5.12kg/kg RecycleRecycle (Edupack, 2006) The above characteristics result ceramic materials being the optimum material for ball bearings; High speed, faster acceleration this is because ceramics are only 40% as dense as steel. However, the material can deliver 30-50% higher running speeds with reduced skidding and less lubrication needed. Lighter in weight ceramic ball bearings are more rigid to that of steel ball bearings and lighter in weight.   This allows for lower coefficients and a higher overall RPM (rotation per minute) Greater accuracy since ceramics has 50% higher modulus of elasticity than steel. This means less of a deformation which leads to vibration and spindle deflection, this increases components productivity and quality. Reduced friction: benefits of this include: longer life, energy efficiency reduced noise levels, less heat and less lubrication needed. Non-conductive materials like Silicon nitride eliminate the pitting and fluting of raceways which ic common in electrical motor applications. If steel is used in bearings the electricity could cause magnetic field (EMF) and this could act as a conducted damaging the bearings over time. Ceramic materials are immune to EMF, which mean they perform well even when electricity is present. Corrosion resistance Silicon nitride; more effective than steel balls in the presence of liquids such as water or corrosive materials. Corrosion resistance can be enhanced when ceramic balls are used with dry fil, lubricant on the ring and retainer components. Longer operating life Up to 5 to 10 times longer than standard metal bearings. Higher temperature operation ceramic ball bearings can operate in high temperatures (up to 1,800  °F) Less noise and vibration due to a lower coefficient of friction (Ibsco, 2011) The two materials chose were Silicon Nitride and Zirconia. A brief description can be seen below outlining why the individual ceramic is the optimum choice; Silicon Nitride: This material contains high temperature capabilities, meaning it has a low thermal expansion coefficient which gives good thermal shock resistance compared to other ceramic materials. The material is up to 58% lighter than steel silicon (Carter, 2009). As the material is lighter it means a smaller force is needed to roll the element. The main advantage to this is that silicon nitride can carry similar loads to that of silicon steel with less force needed. Zirconia: Zirconia was made for high performance duties such as (atmospheric journeys). This means the material has the highest temperature ability. However, this material has a high thermal expansion (almost like steel) but weighs less so it does not have the same weight saving and thermal shock resistance found in other ceramic materials. (Carter, 2009) Zirconia is used when low loads are applied or when high temperature capabilities are needed (corrosive too). (iii) Porosity refers to a measure of void (empty spaces in a material) and is a fraction of the volume of voids over the total volume between 0% and 100% (Quora, 2003) Technical ceramics do not have open porosity. To achieve porosity manufacturing process must be done (use of additives). This then allows closed and open pores to be created, ranging from nm to  µm. Porosity can have various effects on the mechanical properties of ceramics (as chosen). The following properties are effected: Compressive strength Density Fatigue Youngs modulus Fracture toughness Shear modulus Tensile strength Any residual porosity will influence elastic properties and strength. For some materials, the magnitude of the modulus of elasticity E decreases with volume fraction per; It is known that porosity affects flexural strength as it reduces cross-sectional area. It also results in pores acting as stress concentrates. (Duffy, 2010) (iv) Below is a completed table for ceramic materials having 20vol% porosity. This is done by using the following; The below calculation for silicon nitride is done for clarity; ) = 199.424 GPa Where is the modulus of elasticity and is the porosity volume. Table 5 Ceramic materials with 20vol% Material Modulus of Elasticity GPa Porosity at 20vol% E(20%) Porosity GPa Silicon nitirde 304 0.2 199.424 Zirconia 205 0.2 134.48 Silicon carbide 345 0.2 226.32 Aluminum oxide 393 0.2 257.808 Glass-ceramic 120 0.2 78.72 Mullite 145 0.2 95.12 Spinel 260 0.2 170.56 Magnesium oxide 225 0.2 147.6 Fused silica 73 0.2 47.888 Soda-lime glass 69 0.2 45.264 As seen from the above, silicon nitride is the ceramic material resulting in a modulus of elasticity when having a porosity volume of 20%. References Carter, 2009. Carter. [Online] Available at: http://www.carterbearings.co.uk/unasis/hybrid-and-ceramic-bearings/ceramic-matericals-and-their-properties-part-2/[Accessed Saturday Feburary 2017]. Duffy, J., 2010. Moodle. [Online] Available at: http://moodle.itb.ie/pluginfile.php/115304/mod_resource/content/0/CES%20EduPack%20-%20USEFUL%20SOLUTIONS%20to%20COMMON%20PROBLEMS%202008%20-%2001Jan13.pdf[Accessed Wednesday Feburary 2017]. Edupack, C., 2006. s.l.: s.n. Ibsco, 2011. Ibsco. [Online] Available at: http://www.ibsco.com/ceramic-ball-bearings.php[Accessed Saturday Feburary 2017]. Quora, 2003. Quora. [Online] Available at: 2017[Accessed Wednesday Feburary 2017].

Nelson Mandela :: essays research papers

Nelson Mandela's greatest pleasure, his most private moment, is watching the sun set with the music of Handel or Tchaikovsky playing. Locked up in his cell during daylight hours, deprived of music, both these simple pleasures were denied him for decades. With his fellow prisoners, concerts were organised when possible, particularly at Christmas time, where they would sing. Nelson Mandela finds music very uplifting, and takes a keen interest not only in European classical music but also in African choral music and the many talents in South African music. But one voice stands out above all - that of Paul Robeson, whom he describes as our hero. The years in jail reinforced habits that were already entrenched: the disciplined eating regime of an athlete began in the 1940s, as did the early morning exercise. Still today Nelson Mandela is up by 4.30am, irrespective of how late he has worked the previous evening. By 5am he has begun his exercise routine that lasts at least an hour. Breakfast is by 6.30, when the days newspapers are read. The day s work has begun. With a standard working day of at least 12 hours, time management is critical and Nelson Mandela is extremely impatient with unpunctuality, regarding it as insulting to those you are dealing with. When speaking of the extensive travelling he has undertaken since his release from prison, Nelson Mandela says: I was helped when preparing for my release by the biography of Pandit Nehru, who wrote of what happens when you leave jail. My daughter Zinzi says that she grew up without a father, who, when he returned, became a father of the nation. This has placed a great responsibility of my shoulders. And wherever I travel, I immediately begin to miss the familiar - the mine dumps, the colour and smell that is uniquely South African, and, above all, the people. I do not like to be away for any length of time. For me, there is no place like home. Mandela accepted the Nobel Peace Prize as an accolade to all people who have worked for peace and stood against racism. It was as much an award to his person as it was to the ANC and all South Africa s people. In particular, he regards it as a tribute to the people of Norway who stood against apartheid while many in the world were silent.